[Krod67]

I have this diff but not sure what it is. It has no markings on it other that B-604 engraved in it. I'm assuming its for a GM 12 bolt, but not sure exactly what it fits. The bolt circle is 6.25" and it has 12 bolts on the ring gear.

Thanks for your help

 

[WashedUp]

Looks like a Winters.

 

[Krod67]

Looks like a Winters.

Thanks

 

[WashedUp]

No problem. Looks like an older Winters quick change diff. Not a 12 bolt.

 

[Krod67]

No problem. Looks like an older Winters quick change diff. Not a 12 bolt.

I called Winters and they said it's possible that it's theirs but like you said, it's an older unit.